Electrical connector having a resiliently biased automatic latch



Oct. 23, 1951 E. s. CHILLD 2,572,448

ELECTRICAL CONNECTOR HAVING A RESILIENTLY BIASED AUTOMATIC LATCH FiledJan. 29, 1949 5 Sheets-Sheet l 3 Sheets-Sheet 2 INVENTOR. f/(f/Fffi" a".07/10 BY ATTORNEY E. S. CHILD Oct. 23, 1951 ELECTRICAL CONNECTOR HAVINGA RESILIENTLY BIASED AUTOMATIC LATCH Filed Jan. 29, 1949 Oct. 23, 1951E. s. CHILD 2,572,448

ELECTRICAL CONNECTOR HAVINGA RESILIENTLY BIASED AUTOMATIC LATCH FiledJan. 29, 1949 3 Sheets-Sheet 3 AT T ORNEY Patented Oct. 23, 1951ELECTRICAL CONNECTOR HAVING A RE- SILIENTLY BIASED AUTOMATIC LATCHEverett S. Child, Barrington, R. I., assignor to United States RubberCompany, New York, N. Y., a corporation of New Jersey ApplicationJanuary 29, 1949, Serial No. 73,621

8 Claims. 1

This invention relates to an improved electrical terminal adapted to beconnected to a like terminal and a protecting cap for such terminal. Thesubject matter disclosed and claimed herein is a continuation-in-part ofmy former application Serial No. 717,646, filed December 21, 1946, nowabandoned.

The locking connection is useful for preventing electrical cableterminals from becoming separated and also for retaining them in tightengagement to form a fluid tight seal for the completely enclosedelectrical contacts and locking member. Electrical terminals having theabove characteristics are particularly useful for connecting power linesand communication cables which are subjected to outdoor weatherconditions, and to being pulled over the ground or other rough handling.Such conditions require the electrical contacts to be sealed againstwater and dirt, and that all external projections be eliminated toprevent the connection from catching fixed objects. In order to protectthe terminals against damage from handling and moisture before they areconnected, the terminals are provided with protective caps.

Among the objects of this invention is to provide a locking connectionbetween separable lengths of an electrical cable which has a smoothoutline, and a water-proof enclosure for the locking mechanism andelectrical contacts. Another object is to protect the unconnected cableterminal.

A further object is to make the connected parts alike so that eachinterlocks with the other.

A still further object is to provide a construction that can be readilycoupled and uncoupled without the use of tools.

The foregoing and other objects of this invention will be more clearlyunderstood by referring to the following description, and theaccompanying drawings, in which:

Fig. 1 is a cross-sectional view of an electrical terminal comprisingone part of the connection embodying this invention, taken on line l--lof Fig. 2.

Fig. 2 is an end view of the terminal shown in Fig. 1;

Fig. 3 is a view of the disconnected locking connection, showing the twolike parts, one of which is incorporated in each of the terminals;

Fig. 4 is a view of the parts shown in Fig. 3 after being connected;

Fig. 5 is an end view of one part of the locking connection shown inFig. 3, with an outer sleeve added;

Fig. 6 is an elevational View of the guiding and aligning member of thelocking connection;

Fig. 7 is a view of the member shown in Fig. 6, but turned through anangle of Fig. 8 is a cross-sectional view of a cable terminal taken online 8-8 of Fig. 2, and showing a similar cross-section of a protectivecap for the terminal;

Fig. 9 is a cross-sectional view similar to that shown in Fig. 8, butshowing the protective cap secured on the cable terminal;

Fig. 10 is an elevational view of the engaging end face of theprotective cap;

Fig. 11 is a longitudinal cross-section of a modified form of a terminalembodying this invention taken on line |l--ll of Fig. 12;

Fig. 12 is an end view of the terminal shown in Fig. 11; and

Fig. 13 is a cross-section of two like terminals being connected.

An embodiment of the invention is shown in Figs. 1 to 10 of the drawingsas an electrical cable terminal. As both of the terminals are alike onlone complete terminal is illustrated and described in connection withthe modification in Figs. 1 to 10. Referring particularly to Figs. 1 and2, the terminal I0 is provided with male and female contact members lland 12, respectively, which are arranged in a circle around one part 13of a locking connection I4. When two of the terminals I!) are connectedtogether, the male contact members ll of one terminal telescope withinthe female contact members I2 of the other terminal, while the likeparts I3 of the locking connection engage one another, as shown in Fig.4, and thereby secure the terminals l0 together. The contact terminals Hand i2 and the parts [3 of the locking connection are enclosed in a softor deformable resilient waterproof casing I5, which may be made of arubber or rubber-like composition. An annular ridge [6 is formed on theend face of each of the terminals. The resilient ridge It on oneterminal abuts against the ridge on the other terminal lil when they areconnected, and form a waterproof seal around the contact members and thelocking connection 14.

The contact members II and [2 are supported in hard pressed fiber discsI1, and a conductor l8 extending from a cable I9 is connected to eachcontact member. The cable l9, containing a plurality of the conductorsl8, passes through and is anchored to a base ring 20, which supports thelocking connection parts l3 by means of a yoke 2| extending upwardlyfrom the ring Zil. A

brass sleeve 22 extends around the outer end of part l3 from the end ofthe yoke 2| to the end of the rubber casing [5. The water-proof rubbercasing I is molded around and encloses the bases of the contact membersII and I2, the sleeve 22, the end of the cable l9, and the rigidsupports therefor. The contacts and connected metal parts are therebyelectrically insulated b! the rubber 15.

The separated parts [3 of the locking connection Hi are shown in Fig. 3in their relative positions prior to their engagement with one another.central aligning and guiding member 23- around which is located threeprojections 24 provided with overhanging shoulders forming locking hooks25. The radial faces 25.0f the projections,

24 are inclined to the axis of the circle about which they are arranged.The inclination is' in the nature of a helix and as shown herein it hasaleft handtwist. Thealigning and guiding member 23 has generally theshape of a'half cylinder. As shown in Figs. Band '7, the outer end ofthe member 23 is provided with a fiat side 21, and has a sector shapedrecess 28- extending inwardly therefrom.

In order to connect two of the terminals It together, the faces ofthe'terminals are brought towards each other with the flat ends 2'! ofthe guiding and aligning members 23 in sliding contact. When theterminals are so oriented by the fiat ends 27, the male contact membersH are axially aligned with and arranged in posi tion to extend into thefemale members 62'. It

will be noted that since'the ends of the male members H extend outwardlybeyond the ends of the locking projections 23 and female members I2(which latter ends are at the same. level) the telescoping action ofthemale and female contact members will begin before the ends of thelocking projections 24 on the respective terminals begin to mesh withone another. Upon pushing the faces of the terminals closer together,the locking projections 22 on one terminal extend into the space 29between and mesh with those of the other.

v The longitudinal axes of the male and female contact members areparallel to the axis of the cable terminal, and such contact members onopposed terminals engage'each other. in a straight line motion, whereasthe radial faces 26 of the locking projections 23 arearrangedat an angleto or spirally in reference to the axis of the terminal, and suchprojections on opposite terminals engage each other in a spiral motion.Due to the angular arrangement of the faces 26 in respect to the axes ofthe contact members I1 and I2, and the sliding helical movement of theopposing faces 26 of the projections 22 on one another, as the terminalsare pushed together, torsional strains are set up in the rubber betweenthe locking members '24 and the contact members in the terminals. Thecontact members I I and [2 being mounted in soft resilient rubber, theyare permitted to move against the resistance of the rubber about thelocking projections and through the radial angle required for the hookson the projections 2 of each terminal to pass axially inwardly beyondone another. When the hooks 25 are opposite each other, the resilientaction of the rubber casing [5, resulting from the torsional strains,forces the overhanging faces of the hooks into locking engagement asshown in Fig. 4, by rotating the parts relatively to each other asindicated by the arrows A. The sealing Each of the parts [3 is providedwith a or other suitable material.

ridges It are thus pressed into tight engagement with each other andthey form a fluid proof seal between the faces of the terminals. Theseal extends completely around their outer margin.

The torsional strains in the rubber casing l5 maintain the lockedconnection, until some outside force or forces turn one-terminal inrespect to the other in the direction opposite to the arrows A, in Fig.4, so as to overcome the resilient action of the rubber body l5, and atthe same time pull the terminals away from one another. This may be doneby grasping the terminals, one with each hand, and rotating and pullingthe terminals apart as indicated.

When the locking connections 14 are being pushed together, the'rotationof one with respect tothe other takes place after the flat ends 21 passover one another, and then one half of each end rotates into the angularrecess 28, on the guiding and aligning members 2'3. When the terminalsH) are pulled apart, the rotation of the aligning. and guiding members23 in the direction of the arrows A ceases when the fiat ends 21 of therespective terminals in begin to engage one another, and in thatposition they are again parallel.

Figs. 8 to 10 disclose a cable terminal In, similar to that shown inFigs. 1 and 2, and also discloses a protective cap 30-for the cableterminal. by a chain 3! in order that it may be held in readiness toengage the cable terminal l0 when one cable terminal is separated fromanother.

The cap Sitcomprises projections 32 which are adapted to telescope withthe hollow, or female contact members l2 inthe cable terminal 10.

Two or more of the projections 32 are looselyanchored in a rigid disc33-on a circle about the center of the disc, which-may be made of metalis formed by inserting the flanged ends 34-of the projections 32 intoslots 35, which extend from the edge of the disc radially inward. Thewidth of the slots 35 is greater than the diameter of the ends 34between the flanges 36 and 31 which are spaced from each side of thedisc 33. The ends 34 of the projections 32 and the disc 33 are embeddedin a body 33 of a soft rubber-like ma' terial, which is molded aroundthese members in such a manner that the outer ends 39 of the projections32 have some resilient movement in respect to the disc 33, but isnormally retained by the rubber in alignment with the hollow femalecontacts I2. Three locking projections 40 are rigidly secured to thedisc 33 on a circle concentric with the circle on which the projections32 are arranged. Such locking projec-- tions are identical with, andadapted to interlock with the lockin projections 24 on the terminal i0.jections 40 there isarranged a guiding member 4|, which is similar to,but slightly different in shape from, the guiding member 230i the cableterminal IE]. As shown in. Fig. 1f), the guiding member 4! has a sectorshaped cross-sectional area throughout, and coversan are slightly lessthan that of a semi-circle. The outside angle tween the radial sides(and 43 (Fig. 10) is the same as the outside angle between the radialsides of terminalguide member 2] opposite the recess 28, and is greaterthan by the amount the locking projections 45 must rotate during theiraxially directed engaging motion with the terminallocking projections.24.-

The cap 30 is assembled on the terminal; lfljin;

The cap 33 is attached to the cable l9 The loose anchorage- Within thecircle of the locking prosomewhat the same manner heretofore describedfor the connection of two of the like terminals [0. The construction ofthe cap is slightly different from the construction of the cableterminal Ill, and because of such difference, the coaction of the capand terminal differs slightly from the co-action between two terminalsduring their locking movements. In the case of the cap 30 the guidemember is not provided with a flat diametrical end like the end 21 onthe cable terminal I0, and the ends of the telescoping projections 32 donot extend beyond the ends of the lockin projections 48. In connectingthe cap 30 to the terminal H), the side 42 of the cap guide member 4| isplaced against the flat end 21 of the terminal guide member 23, and ascap 38 is moved towards the terminal l0, first the locking projections40 extends into the spaces 29 between the corresponding lookingprojections 24 of the cable terminal, and then the projections 32 beginto telescope with the female contacts I2. There is suflicient play ortolerance in the fit of the parts to permit the initial telescopingaction of the parts 48, 24 and 32, 12, respectively, to take placewithout setting up any strains in the rubber. After engagement of theprojections 32 and the contacts I 2, the relative helical slidingmovement between the inclined faces 44 and 26 in opposition to thestraight line or axial movement of the projections 32 into the contactsl2, sets up torsional strains in the rubber 38 and I5. As the axialengaging movement is continued, the projections 48 are rotated in acounter-clockwise direction (as viewed in Fig. 8) in respect to theprojections 24 and against the resilient resistance of the rubbertransmitted through the projections 32. When the locking hooks 45 on theprojections 48 pass over the locking hooks 25 on the projections 24, theresilient action of the projections 32 rotates the projections 48 in aclockwise direction so that the hoolm interlock one another in theposition shown in Fig. 9.

When the cap 30 is connected to the terminal 10, the outer edge 46 onthe cap 38 engaged the perimeter of the casing l5 and the outside of thesealing ridge l6, and thereby forms a liquid-proof seal between thecontacting parts, and encloses the electrical contacts II and [2. Whenso connected, the outer edge 46 and ridge l6 are deformed undercompression against each other, but for clarity of illustration suchdeformity is not indicated in the drawings. The enclosure formed by thecap 38 protects the electrical terminals from mechanical injury anddamage from moisture during the handling of the cables while two likecable terminals ID are disengaged.

A modified form of an improved electrical terminal embodying thisinvention is shown in Figs. 11 to 13 of the drawings, in which thelocking projections for retaining the two like cable terminals in theirconnected relationship are placed on a circle circumscribed about theelectrical contacts, instead of being placed within the circle on whichthe electrical contacts are located. This form of terminal is alsoprovided with a different type of aligning and guiding member, as willbe hereinafter described.

Referring to Figs. 11 and 12, the electrical contacts are resilientlymounted in a deformable soft rubber, or rubber-like body 41, which issecured to a sleeve 48, on which an outer ring of locking projections 49are formed. The locking sleeve 48 is secured to a metal yoke 58. Arubber casing 5| surrounds the locking sleeve 48 and the yoke 50 and isbonded to the latter. The casing 5| extends downwardly over the cablejacket 52 to which it is bonded so as to unite the terminal parts to thecable end. The conductors 53 extend from the end of the cable jacket 52into the yoke 50, and are connected to the respective electricalcontacts.

The end face 54 of the rubber body 41 is provided with asemi-cylindrical projection 55 within which the female contacts 56 areembedded. The end face is also provided with a complementarysemi-cylindrical recessed portion 51 within which are mounted maleelectrical contacts- 58. The electrical contacts 56 and 58 are initiallymounted in a fiber disc 59, and are placed in a mold together with thelocking projection sleeve 48. The rubber composition 4'1 is then placedin the mold and vulcanized around the contacts and within the sleeve 48.A vulcanized bond is thereby formed between the rubber and such parts.The sleeve 48 may be then secured to the yoke 58 in any suitable manner,as by a pressed fit, or by riveting. The conductors 53 are then solderedon to the projecting ends of the contacts 56 and 58, and such assemblyis placed in a mold, in which the, outer casin of rubber 5! isvulcanized to the yoke and to the cable jacket 52.

The locking projections 49 are provided with helically inclined camsurfaces 80, at the inner end of which is formed overhanging lockingshoulders 8!. As shown in Fig. 13, when two like cable terminals arebeing connected, the diametrical side 62 of the elevatedsemi-cylindrical portions of the rubber bodies 47 are first engaged withone another. The diametrical sides 62 forming aligning and guidingmembers, which are adapted to align the male contacts 58 on one terminalwith the female contacts 56 on the other terminal when such sides arematched together as shown in Fig. 13. As the terminals are forcedtogether in the direction of their axes, the cam surfaces 68 engage oneanother after the contacts on the respective terminals have begun totelescope, and with the continued inward or connecting movement of theterminals the cam surfaces slide over each other and rotate, or displacethe telescoping contacts in respect to the locking projections. When theends of the cam surfaces are reached, the locking shoulders 6! on theopposite terminals slide over each other in a counter rotating movementdue to the resilient energy stored in the rubber body 41 by the rotativemovement of the cams 68. The terminals are thus locked together, andwill remain so locked until the operator turns the casings 5| of therespective terminals in the direction of rotation produced by the camsurfaces so as to disengage the over-hanging shoulders 5! on therespective locking projections from each other. After the shoulders 5!have been disengaged, the terminals may be pulled apart by the operator.When the shoulders 6| of the locking projections 49 are in engagement,the ends 53 of the casing are tightly pressed together and form a fluidtight seal.

While the preferred embodiments of this. invention have been disclosedherein, it will be understood that the details of its construction maybe changed without departing from the spirit of the invention and thescope of the appended claims.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

1. An electrical terminal adapted to be coniieoted t'o alike terminal,said terminal 'compr-i's-- ing abody of soft resilient rubber-likematerial, a plurality of maleand female electrical contacts resilientlymounted in said body and being spaced so that said male contacts on oneterminal ar adapted to telescope with the female contacts on the otherterminal, locking projections mounted in said body, said projections onone terminal having helical cam faces adapted to slide on. like facesofthe other interlocking terminal and circumferentially displace saidtelescoping contacts with respect to said projections in opposition. tothe resilient resistance of. said body during the? inward telescopingmovement of said contacts, and overhanging shoulders at the inner endsof. said faces adapted tointerlock With correspond.- ing shouldersonathe other liketerminal under the resilient reaction; of saidibody.

2. An; electrical terminal adapted to be connectedand locked toaliketerminal, said terminal. comprising a deformable resilient rubber-likebody of material, a plurality of electrical contacts, resilientlymounted on a circle in said body, said contacts on one terminal beingadapted to slide over the contacts of the other terminal in thedirection of the axis of said circle, locking projections connected tosaid rubber body and spaced from said contacts on a circlecircurnscribed about said axis, said projections on one terminal havinghelical cam surfaces adapted to slide on like cam surfaces of thelocking projections on the other terminal and thereby radially displacethe contacts of the interlocking terminals inopposition to the resilientresistance of said rubber-like body during the connecting movemeritv ofsaid contacts, and overhanging shoulders at the inner ends of said camsurfaces adapted to interlock with corresponding shoulders of the otherprojections of the-like terminal under the resilient reactionofsaidresilient rubber-like body at the end of said connecting movement ofsaid terminal.

3. An electrical terminal as in claim 1, wherein said lockingprojections are located on a small circle, and anaxial guide is fixed insaid circle and extends beyond the initial point of engagement ofsaid'other elements of said terminal and is adapted to slide over thecorresponding-element of the mating terminal during the connectingoperation.

4. An electrical terminal as in claim 1, whereinsaid locking projectionsare located on an inner circle concentric with said contacts, an axialguide locking terminal for initially aligning said male contacts on oneterminal with said female contacts on the other terminal, and thelengths of said guides, contacts and locking projections beingproportioned to cause said members to err-- gage each other in the orderlast named during the terminal connecting operation.

5. In combination, an electrical cable terminal and a protective captherefor, said terminal com-- prising a resilient rubber-likecylindrical body of waterproof material forming a casing; said terminalcomprising a plurality of electrical con tacts and locking projectionsmounted respectively on outer and inner concentriccircles in saidterminal body, said contacts and locking projectionsbeingresilientlysupported by said casing.

so that. the .contacts are adapted-to be moved relatively'with respecttosaid locking projections; saidlo'cking'projections having spirallyinclined faces provided with looking notches, said protective capcomprising a body, pins anchored in said body and adapted to telescopewith said terminal contacts by a straight'line axial movement, looking'projections anchored in said cap body, saidlast mentioned lockingprojections corresponding to and adapted to interlock with said terminallocking projections upon moving along said spirally inclined-facesagainst the resilient resistance offered by the straight line'telescoping movement of said-pins with said terminal contacts.

6. Incombination, an electrical cable terminal andia' protective captherefor, said terminal and cap each comprising-'2'. resilientrubber-like cylindrical body of water-proof material forming a casing,said. terminal comprising a plurality of electrical contacts and lockingprbje'c'tio'ns mounted respectively'on outer and inner concentriccircles in said terminal body; a guide member wholly Within said innercircle" and rigidly connected'to' said' locking projections, saidcontacts and'locking projections being resiliently supported sothat thecontacts are adapted to be moved relatively with respect to said lockingprojections; said locking projections having. spirally inclined facesprovided with notches, said protective cap comprising a guide memberadapted toslide and rock on said terminal guide member, projectionsadapted to telescope with said terminal contacts, locking projectionscorresponding to and'adapted to interlock with said terminal lockingprojections, all of said projections and the guide? member of said capbeing mounted in said cap body, and said cap body having an outerperipheral sealing edge which is adapted'to contact witha correspondingsealingedge on said terminal body'vvhen said cap is interlocked withsaid terminal.

'7. An electrical terminal adapted to be connectedand locked to aliketerminal, said terminal comprising a deformable resilient rubberlikebody of material having elevated and depressed end face portions, aplurality of female contacts resiliently, mounted and substantiallyembedded in said elevated portion of said body, a plurality of malecontacts resiliently mounted in said depressed portion, said contacts onone terminal being adapted to make slidingcontact with the contacts" ofthe other terminal during the connecting and disconnecting movements ofsaid terminals, locking projections connected to said'rubber body andspaced from said contacts on a circle surrounding said elevated and dcpressedend face portions, said projections on one terminalhaving'helic'al cain'surfaces adapted to slide on like cam surfaces ofthe locking projections on the other: terminal and thereby rotate saidlocking projections on one terminal in respect to those on theothertermina-l and displace the contacts of the'interlocking terminalsin op position to the resilient resistance of said rubber.- like bodyduring the connecting movement of said contacts, and overhangingshouldersat the inner ends of said cam'surfaces' adapted to inter-' lockwith corresponding shoulders on the other like terminal under theresilient reaction of said resilient rubber-like body at the end of saidconnecting movement of said terminals.

8. An electrical terminal adapted to be con nected and locked to' alike: terminal comprising a deformable resilient rubber-like body ofmaterial having-semi cylindricali elevated and do pressed. end face-=portions=provided. with dram eters of the same size and lying in thesame plane, a plurality of female contacts substantially embedded insaid elevated portion, a plurality of male contacts mounted in saiddepressed portion, said female and male contacts being adapted totelescope with the respective male and female contacts of the liketerminal during the connecting movement of said terminals, lockingprojections secured to said rubber-like body and spaced from saidcontacts on a circle surrounding said elevated and depressed end faceportions, helical cam surfaces on said locking projections adapted toslide over the cam surfaces of the like terminal and rotate thetelescoping male and female contacts in respect to said lockingprojections during the connecting movement of said terminals, andoverhanging shoulders at the inner ends of said cam surfaces adapted tointerlock with corresponding shoulders on the other like terminal underthe resilient reaction of said rubber-like body at the end of saidconnecting movement of said terminals,

EVERETT S. CHILD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS-

